WO2009039021A1

WO2009039021A1 - Fuel injector assembly including fuel injector retention device

Info

Publication number: WO2009039021A1
Application number: PCT/US2008/075933
Authority: WO
Inventors: Janusz Szatkowski; Gary Klinger; Mark Whatley
Original assignee: Cooper-Standard Automotive Inc.
Priority date: 2007-09-18
Filing date: 2008-09-11
Publication date: 2009-03-26

Abstract

A fuel injector assembly includes a fuel rail having at least one cup, a fuel injector and a retention device. The fuel injector is at least partially received within the at least one cup. The retention device secures the fuel injector to the at least one cup and divides a load acting upon the fuel injector between a first cross-sectional area of the fuel injector assembly and a second cross-sectional area of the fuel injector assembly.

Description

FUEL INJECTOR ASSEMBLY INCLUDING FUEL INJECTOR

RETENTION DEVICE

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Application No. 60/973,220, filed September 18, 2007 and U.S. Provisional Application No. 60/992,432, filed December 5, 2007.

BACKGROUND OF THE DISCLOSURE

[0002] This disclosure generally relates to a fuel injector assembly, and more particularly to a retention device for securing a fuel injector relative to a fuel rail.

[0003] Fuel injector systems are known for delivering fuel to the cylinders of an internal combustion engine. The fuel injection system draws fuel from a fuel tank with a fuel pump and communicates the fuel to a fuel rail mounted adjacent to the cylinder blocks of the engine. In a direct fuel injection system, the fuel injectors suspend from cup portions of the fuel rail and receive pressurized fuel from the fuel rail.

[0004] When the injector is energized (i.e., the vehicle engine is running), an electromagnet translates a plunger that opens the fuel injector valve, and allows the pressurized fuel received from the fuel rail to be communicated through a tiny nozzle. The fuel injector nozzle is designed to atomize the fuel. That is, the nozzle converts the fuel into a fine mist such that the fuel can be easily burned once sprayed into the intake valves of each cylinder of the engine. Typically, one fuel injector is associated with each cylinder of the internal combustion engine.

[0005] During engine operation, high frequency noises are generated by the mechanical movement of the fuel injector and low pressure frequency pressure waves are generated by the communication of the fuel through the fuel injection system. These high and low frequency noises travel through the fuel rail and can cause unwanted noise. Additionally, the cup portions of the fuel rail can act like a drum and amplify the unwanted noises. Audible noises of this type are annoying and may be unacceptable to the vehicle operator. Prior art attempts to reduce these audible noises, including the use of dampers and acoustic covers, have not adequately reduced the audible noises in a cost effective manner. [0006] Additionally, fuel injectors are subject to high pressures during the fuel injection process. The pressures may become severe enough that the fuel injector separates from the cup of the fuel rail.

SUMMARY OF THE DISCLOSURE

[0007] A fuel injector assembly includes a fuel rail having at least one cup, a fuel injector and a retention device. The fuel injector is at least partially received within the at least one cup. The retention device secures the fuel injector to the at least one cup and divides a load acting upon the fuel injector between a first cross- sectional area of the fuel injector assembly and a second cross-sectional area of the fuel injector assembly.

[0008] A method of retaining a fuel injector to a cup of a fuel rail includes supporting a seal assembly within the cup of the fuel rail with a first retention device, and securing the fuel injector relative to the cup of the fuel rail with a second, different retention device.

[0009] A method of controlling a load communicated to a fuel injector of a fuel injector assembly having a fuel rail, a fuel rail cup and the fuel injector includes dividing the load between a first cross sectional area and a second cross sectional area of the fuel injector assembly. [00010] The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS [00011] Figure 1 illustrates an example fuel injection system;

[oooi2] Figure 2 illustrates an example fuel injector for use within the fuel injection system illustrated in Figure 1;

[oooi3] Figure 3 illustrates another example fuel injector having an O-ring damper; [oooi4] Figure 4 illustrates yet another example fuel injector having a polymer disk damper;

[oooi5] Figure 5 illustrates one example polymer disk damper; [00016] Figure 6 illustrates another example polymer disk damper; [00017] Figure 7 illustrates another example fuel injector having a nose cone polymer damper;

[00018] Figure 8 illustrates an example mounting bracket for mounting a fuel injector within an example fuel injection system; [oooi9] Figure 9 illustrates a cross-sectional view of fuel injector received within a mounting bracket of the fuel injection system illustrated in Figure 8;

[00020] Figure 10 illustrates another cross-sectional view of a fuel injector received in a mounting bracket of the fuel injection system illustrated in Figure 8;

[00021] Figure 11 illustrates yet another fuel injection system; [00022] Figure 12 illustrates yet another fuel injector assembly;

[00023] Figure 13 is a cross-sectional view of the fuel injector assembly of Figure 12;

[00024] Figure 14 illustrates an example fuel injector for use within the fuel injector assembly illustrated in Figure 12; [00025] Figure 15 illustrates an example retention device for use with the fuel injector assembly illustrated in Figure 12;

[00026] Figure 16 illustrates yet another feature of the example fuel injector assembly of Figure 12.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENT

[00027] Figure 1 illustrates a fuel injection system 10 that includes a fuel pump 12, fuel lines 14, a fuel rail 16 and fuel injectors 18. The fuel pump 12 pumps fuel from a fuel tank and communicates the fuel through the fuel lines 14 to the fuel rail 16. The fuel rail 16 includes a plurality of cups 20 that each receives a fuel injector 18 in a pressurized state. The fuel travels from the fuel rail 16 to each fuel injector 18. The fuel injectors 18 are operable to deliver fuel into an intake valve of each cylinder of an internal combustion engine 22. In one example, the fuel injection system 10 is a direct injection type fuel injection system. However, it should be understood that other fuel injection systems are contemplated as within the scope of the present invention.

[00028] Figure 2 illustrates an example fuel injector assembly 24. In the illustrated example, the fuel injector assembly 24 includes a fuel injector 18 and a fuel rail 16 having at least one cup 20. The fuel injector 18 is affixed to the cup 20 of the fuel rail 16 with a retainer 26. An inlet portion 28 of the fuel injector 18 includes a pair of notches 30 disposed on opposite sides of the inlet portion 28, in one example. The cup 20 includes a pair of corresponding slots 32 on opposing sides of the cup 20. The notches 30 and the slots 32 are aligned as the injector 18 is inserted into the recess of the cup 20. The retainer 26 is snap-fit into the slots 32 and the notches 30 to retain the injector 18 within the cup 20 and properly position the injector 18 relative to both the cup 20 and the intake valve of the engine 22.

[00029] A seal 34 is received on the inlet portion 28 of the fuel injector 18 and is positioned between the cup 20 and the fuel injector 18 when assembled. In one example, the seal 34 includes an annular O-ring seal. A flange 36 is defined between the inlet portion 28 and an injector body 38 of the fuel injector 18. A damper 40 is received over the inlet portion 28 and rests against the flange 36 of the injector body 38. In one example, the damper 40 includes a wave washer. However, other dampers are contemplated as when the scope of this invention. The damper 40 maintains the vertical positioning of the fuel injector 18 and reduces the amount of pushback experienced by the fuel injector 18 as the fuel injector 18 injects the high pressure fuel into a corresponding intake valve of the engine 22.

[00030] Figure 3 illustrates another example fuel injector assembly 42. The fuel injector assembly 42 includes a retainer 26, a fuel rail 16 having cups 20 including a pair of slots 32. In this example, these components are substantially similar to the retainer, notches and slots illustrated with respect to the fuel injector assembly 24. The injector body 38 includes a groove 39 that aligns with the slots 32 to receive the retainer 26.

[00031] The fuel injector assembly 42 also includes a seal 44 received within a groove 46 of an inlet portion 48. The inlet portion 48 receives a damper 50 near its distal end 52. In one example, the damper 50 includes a compression O-ring damper. In another example, the distal end 42 of the inlet portion 48 receives a polymer disk damper (see Figure 4). The polymer disk damper illustrated in Figure 4 may include either an OD groove polymer disk damper (see Figure 5) or an ID pressure bellow damper (see Figure 6). In still another example, the distal end 52 of the inlet portion 48 receives a nose cone polymer damper (see Figure 7). A person of ordinary skill in the art having the benefit of this invention would be able to select an appropriate damper for use within the example fuel injector assembly 42.

[00032] Each damper 50 illustrated in Figures 3-7 dampens the vibrations experienced by the fuel injector 18 and properly positions the fuel injectors 18 with respect to the intake valve of the engine 22. Therefore, each damper 50 configuration is operable to reduce the audible noises that may emanate from the fuel injector assembly 42.

[00033] Figure 8 illustrates yet another example fuel injector assembly 54. In this example, the fuel injectors 18 are retained separately from the fuel rail 16. The fuel injector assembly 54 includes a mounting bracket 56 for retaining and maintaining the vertical positioning of the fuel injectors 18. The fuel rail 16 includes a plurality of brackets 58 that are attached to the mounting bracket 56 via fasteners 60. A bracket isolator 62 is positioned between each bracket 58 and the mounting bracket 56 to dampen the vibrations experienced by the fuel injector assembly 54. Each fuel injector 18 includes a groove 64 extending circumferentially about the injector body 38. The mounting bracket 56 includes a plurality of slotted sections 66 that receive the grooves 64 of the fuel injectors 18 to secure the fuel injectors 18 thereto. The cups 20 of the fuel rail 16 are received over an inlet portion 69 of the fuel injectors 18. [00034] In one example, the slotted sections 66 of the mounting bracket 56 include a grommet 80 (See Figure 9). The grommet 80 is rubber, in one example. The grommet 80 is designed to improve the vertical positioning of the fuel injector 18 and is operable to reduce the audible noises that may emanate from the fuel injector assembly 54. The slotted sections 66 are linear, in one example (See Figure 9). In another example, the slotted sections 66 are curved (See Figure 10).

[00035] Figure 11 illustrates yet another example fuel injector assembly 68. In this example, the fuel injector assembly 68 is not a rigid fuel rail. In contrast, the fuel injector assembly 68 includes flexible tubing 70 that delivers the fuel to each fuel injector 18. In one example, each fuel injector 18 receives fuel from an individual flexible tubing line 70. In another example, the flexible tubing 70 includes high pressure, polymer lined, reinforced flexible tubing. However, a person of ordinary skill in the art having the benefit of this disclosure would be able to select appropriate flexible tubing to deliver the fuel to the fuel injectors 18.

[00036] A pressure fitting 72 is received at a distal end 74 of each flexible tubing line 70. The pressure fittings 72 are received on inlet portions 71 of each fuel injectors 18 to communicate the fuel from the tubing 70 into the intake valves of the engine 22. The fuel injector assembly 68 also includes a mounting bracket 56. In one example, the mounting bracket 56 is substantially similar to the mounting bracket illustrated in Figure 8 with respect to the fuel injector assembly 54. The pressure fittings 72 and the flexible tubing 70 eliminate the sensitivity of the fuel rail 16 to the positioning of the fuel injectors 18. In addition, ambient noises are significantly reduced by eliminating the rigid fuel rail 16.

[00037] Another example fuel injector assembly 90 is illustrated in Figures 12- 16. In this example, the fuel injector assembly 90 includes a fuel injector 92 and a fuel rail 94 having at least one cup 96. Although only a single fuel injector 92 and cup 96 are illustrated, it should be understood that the fuel rail 94 could include a multitude of fuel injectors 92 and cups 96 depending upon the number of cylinders associated with the internal combustion engine 22. The fuel injector 92 is affixed to the cup 96 with a retention device 97, as is further discussed below.

[00038] Figure 13 illustrates retention of the fuel injector 92 relative to the cup 96 with the retention device 97. In this example, the retention device 97 includes a first retention device 98 and a second retention device 120. The first retention device 98 is separate and distinct component from the second retention device 120. That is, the first retention device 98 and the second retention device 120 may include different materials, sizes, configurations etc.

[00039] In one example, the first retention device 98 is positioned at a first cross-sectional area A of the fuel injector 92 and the second retention device 120 is positioned at a second cross-sectional area B of the fuel injector 92. In this way, the example retention device 97 controls a load (i.e., a total force and pressure acting upon fuel injector 92 during operation) acting upon the fuel injector 92. For example, the load is divided between the first retention device 98 and the second retention device 120. Therefore, the load is divided between each of the first cross-sectional area A and the second cross-sectional area B of the fuel injector assembly 90. [00040] An inlet portion 100 of the fuel injector 92 includes a pair of grooves

102 disposed on opposite sides of the inlet portion 100, in one example (see Figure 14). The cup 96 includes a pair of corresponding openings 104 positioned at opposite sides of the cup 96. The grooves 102 and the openings 104 are aligned as the injector 92 is inserted into the recess of the cup 96. The first retention device 98 is inserted into the openings 104 and grooves 102 to retain the injector 92 within the cup 96 and properly position the injector 92 relative to both the cup 96 and the intake valve of the internal combustion engine 22.

[00041] The first retention device 98 of the example fuel injector assembly 90 is a rounded wire clip, in this example. A person of ordinary skill in the art having the benefit of this disclosure would be able to select an appropriate retainer device for attaching the fuel injector 92 to the cup 96. The first retention device 98 includes prongs 106 and a handle arm 108 (Figure 15). The prongs 106 protrude transversely from the handle arm 108. In one example, the handle arm 108 is partially curved relative to the prongs 106. The prongs 106 of the first retention device 98 are received within the openings 104 of the cup 96 to retain the fuel injector 92 relative to the cup 96. The handle arm 108 remains exterior of the cup 96 such that the first retention device 98 may be easily removed during repair or replacement of the fuel injector 92 (see Figure 12). [00042] The fuel injector assembly 90 further includes a seal assembly 109 having a seal 110, a spacer 112, and a relief ring 114. Although a single seal and spacer are shown and described with respect to the seal assembly 109, it should be understood that the seal assembly 109 could include any number of seals, spacers and other components. The second retention device 120 supports each component of the seal assembly 109 such that the orientation and positioning of these components is generally preserved with respect to the cup 96. In one example, the second retention device 120 includes a snap ring. However, a person of ordinary skill in the art would understand that other components are contemplated as within the scope of this disclosure. [00043] In one example, the second retention device 120 supports and positions the seal assembly 109 between a first flange 122 and a second flange 124 of the cup 96. The cup 96 includes a groove 126 for receiving the second retention device 120. In one example, the second retention device 120 is snap fit into the groove 126 of the cup 96. [00044] In one example, the seal 110 is an O-ring. It should be understood, however, that other types of seals may be utilized within the fuel injector assembly 90. The spacer 112 is positioned between the seal 110 and the relief ring 114. The spacer 112 is utilized to preserve the integrity of the seal 110 and the relief ring 114 and to maintain a spacing therebetween. The spacer 112 includes a split washer, in one example.

[00045] The relief ring 114 provides a bearing surface for the injector 92 and reduces the pressure experienced by the injector 92. A shoulder portion 115 of the relief ring 114 abuts the flange 122 of the cup 96. In one example, the relief ring 114 is comprised of a thermoplastic, for example. The relief ring 114 is positioned between the spacer 112 and the second retention device 120. The second retention device 120 is made of a metallic material, such as steel or aluminum, for example. In another example, the second retention device 120 is made of a thermoplastic material. A worker of ordinary skill in the art having the benefit of this disclosure would be able to select appropriate materials for the components of the seal assembly 109 and the second retention device 120.

[00046] A multitude of forces act upon the components of the fuel injector assembly 90 during the fuel injection process. For example, a Force Fl acts upon the fuel injector 92 as fuel is communicated from the fuel rail 94 into the cup 96. A force F2 is experienced by the seal 110 due to interaction between the seal 110 and the cup 96. In this example, the Forces Fl and F2 are counteracted by forces F3 and F4. Force F3 represents the force experienced by the first retention device 98 due to interaction between the first retention device 98 and the cup 96. Force F4 is experienced by the second retention device 120 due to interaction between the second retention device 120 and the cup 96.

[00047] As previously stated, the retention device 97 provides the fuel injector assembly 90 with a pressure dividing feature. That is, inclusion of both the first retention device 98 and the second retention device 120 divides the load acting on the fuel injector 92 between the first retention device 98 and a second retention device 120. Therefore, the first retention device 98 is not required to support the entire load of the force. Retainment of the fuel injector 92 within the cup 96 is improved thereby reducing the risk of separation of the fuel injector 92 from the cup 96.

[00048] Figure 16 illustrates another feature of the fuel injector assembly 90. In this example, the fuel injector 92 includes a spherical surface 150. The spherical surface 150 is positioned adjacent to a flange portion 154 of the fuel injector, in this example. The spherical surface 150 provides 360 degrees of freedom for movement of an outlet end 152 of the fuel injector 92 in any direction. The spherical surface 150 therefore aids in assembly insertion of the outlet end 152 of the fuel injector 92 into a corresponding cylinder of the internal combustion engine 22. [00049] The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this disclosure. For these reasons, the following claims should be studied to determine the true scope and content of this disclosure.

Claims

CLAIMSWhat is claimed is:

1. A fuel injector assembly, comprising: a fuel rail having at least one cup; a fuel injector at least partially received within said at least one cup; and a retention device that secures said fuel injector to said at least one cup and divides a load acting upon said fuel injector between a first cross-sectional area of the fuel injector assembly and a second cross-sectional area of the fuel injector assembly.

2. The assembly as recited in claim 1, wherein said retention device includes a first retention device and a second retention device.

3. The assembly as recited in claim 2, wherein said first retention device is a wire clip and said second retention device is a snap ring, and said load is divided between said wire clip and said snap ring.

4. The assembly as recited in claim 2, wherein said at least one cup includes a groove for receiving said second retention device, and said at least one cup includes openings and said fuel injector includes grooves for receiving said first retention device.

5. The assembly as recited in claim 1, comprising a seal assembly positioned between said at least one cup and said fuel injector.

6. The assembly as recited in claim 5, wherein said seal assembly includes a seal, a spacer and a relief ring.

7. The assembly as recited in claim 5, wherein said seal assembly is supported by a snap ring of said retention device.

8. The assembly as recited in claim 7, wherein said snap ring supports and positions said seal assembly between a first flange and a second flange of said at least one cup.

9. The assembly as recited in claim 1, wherein said fuel injector includes a spherical surface.

10. A method of retaining a fuel injector to a cup of a fuel rail, comprising the steps of: a) supporting a seal assembly within the cup of the fuel rail with a first retention device; and b) securing the fuel injector relative to the cup of the fuel rail with a second, different retention device.

11. The method as recited in claim 10, wherein the first retention device includes a snap ring and said step a) includes the steps of: forming a groove within the cup; inserting the seal assembly within the cup; and receiving the snap ring within the groove of the cup.

12. The method as recited in claim 10, wherein the second, different retention device includes a wire clip, and said step b) includes the steps of: providing openings in the cup; forming grooves on an inlet portion of the fuel injector; aligning the openings of the cup with the grooves of the fuel injector; and inserting the wire clip through the openings and into the grooves.

13. The method as recited in claim 10, comprising the step of: c) dividing a load acting upon the fuel injector between the first retention device and the second, different retention device.

14. The method as recited in claim 10, comprising the steps of: c) positioning the first retention device at a first cross-sectional area of the fuel injector; and d) positioning the second, different retention device at a second cross- sectional area of the fuel injector.

15. The method as recited in claim 10, comprising the steps of: c) forming a spherical surface onto the fuel injector; and d) inserting an outlet end of the fuel injector into a cylinder of an internal combustion engine.

16. A method of controlling a load communicated to a fuel injector of a fuel injector assembly having a fuel rail, a fuel rail cup and the fuel injector, comprising the step of: a) dividing the load between a first cross sectional area and a second cross sectional area of the fuel injector assembly.

17. The method as recited in claim 16, wherein said step a) includes the steps of: positioning a first retention device at the first cross sectional area; and positioning a second retention device at the second cross sectional area.

18. The method as recited in claim 17, wherein the step of positioning the first retention device includes supporting a seal assembly within the fuel rail cup of the fuel rail with the first retention device, and the step of positioning the second retention device includes securing the fuel injector relative to the cup of the fuel rail with the second retention device.